Toddlers are more likely to get anxious, depressed or have eating or sleeping problems if they were born 10 or more weeks premature, research has found.
The researchers say it may be a result of the harsh, alienating environment of neonatal intensive care units, and have called for lower lighting, softer sounds and more contact between mother and baby.
The premature children's parents have reported more concerns about their child's behaviour and socialisation.
They also want better support for parents so developing emotional problems can be headed off before they become entrenched in school-age years.
Experts from the Murdoch Children's Research Institute conducted the study, which was published yesterday in the Journal of the American Academy of Child and Adolescent Psychiatry.
They interviewed parents of children born 10 or more weeks premature at the Royal Women's Hospital, and compared them with infants born at more than 36 weeks' gestation.
"The [premature children's] parents have reported more concerns about their child's behaviour and socialisation," said lead researcher Dr Alicia Spittle. These children were more likely to be depressed, display separation anxiety, have poor attention spans or do less imaginary play.
The problems were seen in 35 per cent of the preterm population, compared with 20 per cent of full-term toddlers.
The level of behavioural problems was not strongly associated with the number of weeks a baby was premature, but did seem to be linked with lower birth weight.
There was probably more than one cause, Dr Spittle said. "It seems likely that when these babies were separated from their parents in the neonatal intensive care unit, there was an impact on the bonding between parent and child," she said.
"There is also the environment of the NICU itself — sensory development occurs in the womb, which is very protective, but outside there is more exposure to lights, sound and touch."
Parental stress, and the physiological effects of being born premature could also be factors. "We need to get parents more involved with the care of their babies in intensive care, improve the bonding and create a more positive sensory environment more similar to the womb, with softer lights and sounds," she said.
Since the study was done some of these ideas have been adopted at Victorian hospitals — at the Royal Women's, for instance, mothers can do regular "kangaroo cuddles" of premature babies, holding them in tiny pouches against their chest instead of the usual plastic life-support tubs.
Previous studies had linked social and emotional developmental problems to premature birth in school-age children. Dr Spittle said her research suggested the problem was starting long before school began. "There is no standard follow-up for premature children — they need to be assessed for these problems earlier on, in hospital or in the community."
The researchers have the support of Janine Stanley, the mother of two-year-old twins, Dane and Cole, who were born at 29 weeks. "They've hit that very naughty stage," she said, "but I have got a lot of support and one or the other might not have even been here, so we are pretty lucky really." The twins spent five days in intensive care and seven weeks in hospital after they were born.
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